The present disclosure is related to gas turbine combustion systems and, more specifically, to a combustor cap module having a retention system. According to one aspect, the retention system facilitates assembly and disassembly of the head end. In another aspect, the cap assembly facilitates cooling of the head end, while providing structural support for components (such as fuel nozzles) installed therein.
Heavy duty gas turbines are widely used for power generation. As illustrated schematically in FIG. 1, a typical heavy duty gas turbine includes a compressor section 10, a combustor section 20, a turbine section 30, and a load 40. The compressor section 10 and the turbine section 30 are linked by a common shaft or rotor 12. The compressor section 10 includes multiple stages of rotating blades that compress air, which is provided to the combustor section 20. In the combustor section 20, one or more combustors 22 combusts a mixture of fuel and the compressed air from the compressor section 10 to produce hot combustion gases. The hot combustion gases are directed to the turbine section 30, where the gases drive the rotation of turbine blades in one or more turbine stages. The rotation of the turbine blades drives the shaft 12 to rotate one or more loads 40, e.g., an electrical generator.
The combustor section 20 includes one or more combustors 22, each of which is provided with fuel nozzles to inject fuel and air into a combustor. The fuel nozzles of an individual combustor 22 are contained within a cap assembly. The cap assembly directs the flow of air used for combustion and cooling. One of the challenges in producing such cap assemblies is directing air flow used for combustion and cooling, while maintaining a structure capable of withstanding high vibration loads. Additionally, the design and construction of the cap assembly can significantly affect the time, cost, and complexity of installation, removal, maintenance, and general servicing. Thus, a cap assembly designed as a module for structural stability and installation efficiency would represent an advancement over the current art, which relies heavily on permanent (e.g., welded) joints between the respective components.